java程序中獲取kerberos登陸hadoop

lentoo 發(fā)布于2019-06-28 11:07 / 1116人閱讀

摘要：這中場(chǎng)景下情況會(huì)變得非常復(fù)雜，這時(shí)如果把認(rèn)證的過程移到程序中就會(huì)簡(jiǎn)單很多，每個(gè)程序中獲取各自的憑證，及時(shí)多個(gè)進(jìn)程同時(shí)運(yùn)行也不會(huì)產(chǎn)生相互影響。

本文由作者周梁偉授權(quán)網(wǎng)易云社區(qū)發(fā)布。

一般我們?cè)谑褂胟bs登陸hadoop服務(wù)時(shí)都直接在shell中調(diào)用kinit命令來獲取憑證，這種方式簡(jiǎn)單直接，只要獲取一次憑證之后都可以在該會(huì)話過程中重復(fù)訪問。但是這種方式一個(gè)明顯的問題就是如果在本次shell中會(huì)間隔調(diào)用不同的java程序，而這些程序需要訪問不同權(quán)限的問題，需要在訪問前調(diào)用各自的ktab文件獲得授權(quán)。這中場(chǎng)景下情況會(huì)變得非常復(fù)雜，這時(shí)如果把kbs認(rèn)證的過程移到j(luò)ava程序中就會(huì)簡(jiǎn)單很多，每個(gè)java程序中獲取各自的憑證，及時(shí)多個(gè)進(jìn)程同時(shí)運(yùn)行也不會(huì)產(chǎn)生相互影響。我這里介紹兩種java中獲取kbs憑證的方法，分別使用 org.apache.hadoop.security.SecurityUtil 和 org.apache.hadoop.security.UserGroupInformation 兩個(gè)類實(shí)現(xiàn)。

一、使用ktab文件簡(jiǎn)單登錄方式
登錄操作函數(shù)
/**

  * 嘗試使用kerberos認(rèn)證登錄hfs

  *@params

  *       conf: 配置，其中帶有keytab相關(guān)配置屬性

  *       keytab_KEY: 表示conf中代表keytab文件屬性的鍵值

  *       principal_KEY: 表示conf中代表principal屬性的鍵值

  * @throws IOException

  */

 static void tryKerberosLogin(Configuration conf, String keytab_KEY, String principal_KEY) throws IOException {

      boolean useSec = true;

      LOG.info("Hadoop Security enabled: " + useSec);

      if (!useSec) {

           return;

      }

      try {

           @SuppressWarnings("rawtypes")

           Class c = Class.forName("org.apache.hadoop.security.SecurityUtil");

           // get method login(Configuration, String, String);

           @SuppressWarnings("unchecked")

           Method m = c.getMethod("login", Configuration.class, String.class,

                     String.class);

           m.invoke(null, conf,  keytab_KEY, principal_KEY);

           LOG.info("successfully authenticated with keytab");

      } catch (Exception e) {

           LOG.error(

                     "Flume failed when attempting to authenticate with keytab "

                               + SimpleConfiguration.get().getKerberosKeytab()

                               + " and principal ""

                               + SimpleConfiguration.get().getKerberosPrincipal()

                               + """, e);

           return;

      }

 }

配置
...

flume.security.kerberos.principal

flume.security.kerberos.keytab

resources/flume.keytab

…

Sample

//調(diào)用例子

public FileSystem getFileSystem(Configuration conf) {

           String KEYFILE_key = "flume.security.kerberos.keytab";

           String PRINCIPAL_key = "flume.security.kerberos.principal";



           try {

                // 嘗試用kerberos登錄

                tryKerberosLogin(conf, KEYFILE_key, PRINCIPAL_key);

                // 獲取一個(gè)hdfs實(shí)例

                instance = FileSystem.get( conf);

           } catch (IOException e) {

                LOG.error("try getFileSystem fail()", e);

           } catch (URISyntaxException e) {

                LOG.error("try getFileSystem fail()", e);

           }

      }

      return instance;

 }

二、通過UserGroupInformation獲取代理用戶方式
package com.netease.backend.bigdata.wa.jobs;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.Path;

import org.apache.hadoop.security.UserGroupInformation;

import org.apache.log4j.Logger;

import org.hsqldb.lib.StringUtil;

import com.netease.backend.bigdata.wa.core.ConfKeys;

/**

代理用戶信息認(rèn)證工具

@author zhouliangwei

public class ProxyUGI {

 private static Logger LOG = Logger.getLogger(ProxyUGI.class);



 private static UserGroupInformation instance = null;

 /**

  * 從Configuration中獲取代理用戶的相關(guān)配置，并獲取UserGroupInformation

  * @return

  * @throws IOException

  */

 public synchronized static UserGroupInformation getProxyUGI(Configuration conf) {

      if (instance != null)

           return instance;

      try {

           String username = conf.get(ConfKeys.MR_USER_NAME, "");

           String proxyPrincipal = conf.get(ConfKeys.WDA_PROXY_PRINCIPAL, "");

           String proxyKtab = conf.get(ConfKeys.WDA_PROXY_KEYTAB, "");

           if (StringUtil.isEmpty(username)

                     || StringUtil.isEmpty(proxyPrincipal)

                     || StringUtil.isEmpty(proxyKtab)) {

                LOG.warn("config properties: ["

                          + ConfKeys.MR_USER_NAME

                          + ", "

                          + ConfKeys.WDA_PROXY_PRINCIPAL

                          + ", "

                          + ConfKeys.WDA_PROXY_KEYTAB

                          + "] in config file "./conf/wda-core.xml" must be set!, quite use proxy mechanism");

                return null;

           }

           instance = UserGroupInformation.createProxyUser(username,

                     UserGroupInformation.loginUserFromKeytabAndReturnUGI(

                               proxyPrincipal, proxyKtab));

      } catch (IOException ex) {

           //just ignore;

      }

      return instance;

 }

}

調(diào)用方式
...

public static void main(final String[] args) throws Exception {

      UserGroupInformation ugi = ProxyUGI.getProxyUGI();

      if (ugi != null) {

           ugi.doAs(new PrivilegedExceptionAction() {

                public EventJobClient run() throws Exception {

                     EventJobClient mr = new EventJobClient();

                     int code = ToolRunner.run(mr, args);

                     System.exit(code);

                     return mr;

                }

           });

           System.exit(1);

      } else {

           int exitCode = ToolRunner.run(new EventJobClient(), args);

           System.exit(exitCode);

      }

 }

….

文章來源：網(wǎng)易云社區(qū)